(a) Field of the Invention
The present invention relates to a plug set for optical connector for optical fiber cables and, more particularly, to the construction of a portion thereof for mounting the plug set to the optical fiber cable,
(b) Description of the Prior Art
When mounting known plug sets for optical connectors to optical fiber cables, an inner shield member 2 of an optical fiber cable 1 is inserted into a bushing 11 of a plug set 10 for an optical connector as shown in FIG. 1, reinforcing fibers 3 (for example, made of synthetic resin such as aromatic polyamide) of the optical fiber cable 1 is inserted into a space between an end portion 11a of the bushing 11 and a collar 12, and a tightening nut 13 is screwed onto the bushing 11 in order to thereby fix the plug set to the optical fiber cable. At that time, it is necessary to firmly fix the reinforcing fibers 3 of the optical fiber cable 1 to the plug set 10 of the optical connector. In FIG. 1, numeral 15 designates a frame screwed onto the bushing 11, numeral 16 designates a spring, numeral 17 designates a nut, and numeral 18 designates a ferrule for fixing the end of optical fiber of the optical fiber cable. Therefore, at present, the reinforcing fibers 3 are bonded to the end portion 11a of the bushing 11 by means of a bonding agent and, then, the collar 12 is mounted. However, this method has a disadvantage that the bonding agent adheres to portions other than the portion to be bonded and, consequently, component parts of the plug set become dirty. Besides, it takes time until the bonding agent dries.
FIG. 2 shows another known means for mounting a known plug set for optical connector to an optical fiber cable. In case of this known plug set, an end portion 11'a of a bushing 11' and an end portion 12'a of a collar 12' are formed to have tapered surfaces and it is so arranged that reinforcing fibers 3 are inserted into a space between those tapered surfaces and fixed by tightening a tightening unit 13' so that the reinforcing fibers 3 are thereby held fixedly between the above-mentioned tapered surfaces. In this method, the reinforcing fibers are fixed comparatively powerfully because they are tightened by utilizing the tapered surfaces. However, even in this case, the reinforcing fibers cannot be fixed satisfactorily firmly and, therefore, it is necessary to firmly fix the reinforcing fibers by bonding them using a bonding agent in the same way as the case of known plug set shown in FIG. 1. Consequently, the above-mentioned disadvantages occur also in this case.